On a number line, which of the following sums is to the left of the first number in the sum? Select all that apply. A –9 + 1
B - 1/6 + 4/3
C 7/2 + (-3/4)
D 15+ (–8)
E–2 + 6

The discrete random variables x and y take integer values with joint probability distribution given by f (x, y) = a(y−x+1) 0 ≤ x ≤ y ≤ 2 or =0 otherwise, where a is a constant. 1 tabulate the distribution and show that a = 0.1.2 find the marginal distributions of x and y. 3 calculate cov(x, y).4 state, giving a reason, whether x and y are independent. 5 calculate e(y|x = 1).